The possible disappearance of tiny Independence Air, which edged closer to extinction yesterday with a bankruptcy court filing, could quickly boost fares in the East and leave service gaps for some communities.

In just 17 months of flying as an independent airline, the Dulles, Va.-based Independence Air has forced large competitors to meet or beat its low prices. No. 2 United Airlines, which operates a hub at Independence Air's home airport of Washington Dulles, could benefit from the carrier's disappearance.

Helane Becker, analyst at Benchmark Co., said liquidation of the airline also would benefit JetBlue, US Airways, Delta and Southwest by allowing them to nudge up fares.

In filing for Chapter 11, Independence Air says it expects to continue flying its current schedule for 60 days. What could save it, according to the court filing, is an auction over the next 60 days in which investors could buy all or part of the airline.

But unlike the bankruptcy filings of United, Delta or Northwest, its continuing operation of the airline is less assured.

"This is different from most airline bankruptcies, because there's a good chance of liquidation, and passengers may start booking away," says airline analyst Ray Neidl of Calyon Securities.

Independence Air flies 50 small jets and 12 large jets from Washington Dulles to 36 cities across the East, including Jacksonville, Savannah and Boston. This month, its busiest routes linked Washington Dulles to Boston, Chicago O'Hare, Columbia, S.C., and Atlanta.

Consumers have already felt the impact from Independence Air's struggle to survive. On Oct. 30, the 17-month-old airline stopped flying from Dulles to Indianapolis, Louisville, Cleveland and Newburgh, N.Y. The loss left Newburgh, near Westchester, without direct service to Washington, D.C.

"Customers loved them," says Tanya Vanasse, marketing manager for the Newburgh airport.

Independence Air has its roots in another airline bankruptcy.

Its predecessor company — Atlantic Coast — operated profitably for more than a decade as a regional airline. It operated United commuter flights out of Dulles and Chicago O'Hare and had contracts with Delta.

But when United declared Chapter 11 bankruptcy in 2002, United squeezed its regional airline partners' fees. In response, Atlantic Coast management quit flying for United and took the riskier path of flying alone. It started flying in June 2004 as a discounter under a new name with a new Web site, Flyi.com.

Management dismissed skepticism that 50-seat jets cost too much to operate on shorter routes without adequate fares. They planned to overcome the cost by flying the jets for more hours a day. It started with $350 million in cash to withstand anticipated competition. Under the plan, the carrier was to have broken even in the second half of this year.

Independence Air ramped up faster than any other airline in recent memory. Within three months of its launch, it was one of the nation's biggest discount airlines, with 600 flights a day to 35 cities on 87 aircraft. It flies less than half that number of flights today.